202 Proceedinys of tJte Royal ^ocidij of Victoria. 



Appendix B. 



Oil the. Graptolites of the District. 



By T. 8. Hall, M.A. 



Messrs. Officer and Hogg have kindly placed the graptolites 

 found by them in my hands, and their collection is supplemented 

 by some specimens gathered by myself at localities to which they 

 guided me on a couple of visits in their company. The collection 

 is small and the localities are few, but a very fair idea of the 

 liorizon of the beds can be gained in most cases. 



1. Basin Creek, Coimaidai. 



In blue, very hard, cleaved slates. 



Didytnograptus bifidus, J. Hall ; D. niiinhisoni, Boeck ; D. 

 extensus, J. Hall ; Tetragraptus quad?-ibracJiiatiis, J. Hall ; T. 

 serra, Brong. ; Phyllograptus iypiis, J. Hall ; P. angustifolius, J. 

 Hall. 



The " Tuning-fork Graptolites," of which D. niiirchisoni is 

 typical, seem to occur on a lower horizon in our Victorian rocks 

 than they do in the Northern Hemisphere. In Castlemaine, 

 where the position of the beds containing them is sufficiently 

 clear, they are spai-ingly associated below with the topmost beds 

 containing Tetragraptus friiticosus, rapidly attain their maximum 

 of development and then suddenly disappear. The different 

 forms of Phyllograpiits range far higher than they do and aie 

 abundant long after the niutrhisoni group has died out. With us 

 the " tuning-fork " forms never occur but in association with 

 Phyllograptus, while in Europe at any rate, they appear to be 

 specially typical of beds above those containing PJiyllograptns. 

 It is not a case of PhyUog;raptus ranging higher but of the 

 occurrence of the mitrchisoni group at a lower liorizon for several 

 species of Teiragraptiis, Dichogmptus, etc., occur above it. 

 Messrs. Nicholson and Marr^ regard the niurchisoni group as the 

 direct descendents of Tet. fruficosus, so that its position cannot be 

 considered anomalous. The horizon of the present beds appears 

 identical with that of the " Wattle Gully beds " in Castlemaine.^ 



1 Geological Magazine, 1895, p. fiZh. 



a Proc. Roy. Soe. Vic, N.S., vii., 189.S, p. 70. 



